TY - JOUR
T1 - The influence of fascicle behavior on the lack of velocity dependence in eccentric joint torque in humans
T2 - in Vivo observation
AU - Chino, Kentaro
AU - Mitsukawa, Naotoshi
AU - Kobayashi, Kai
AU - Miyoshi, Yusuke
AU - Oda, Toshiaki
AU - Kanehisa, Hiroaki
AU - Fukunaga, Tetsuo
AU - Fukashiro, Senshi
AU - Kawakami, Yasuo
PY - 2009/5
Y1 - 2009/5
N2 - To investigate the relationship between fascicle behavior and joint torque, the fascicle behavior of the triceps surae during isometric and eccentric (30 and 60 deg/s) plantar flexion by maximal voluntary and submaximal electrical activation (MVA and SEA) was measured by real-time ultrasonography. Eccentric torque at 30 and 60 deg/s was significantly higher than isometric torque under SEA, but not under MVA. However, fascicle length did not significantly differ between isometric and eccentric trials under either condition. Therefore, the difference in developed torque by MVA and SEA cannot be explained by fascicle behavior. Under both MVA and SEA conditions, eccentric torque at 30 and 60 deg/s was equivalent. Similarly, fascicle lengthening velocities at 30 and 60deg/s did not show any significant difference. Such fascicle behavior can be attributed to the influence of tendinous tissue and pennation angle, and lead to a lack of increase in eccentric torque with increasing angular velocity.
AB - To investigate the relationship between fascicle behavior and joint torque, the fascicle behavior of the triceps surae during isometric and eccentric (30 and 60 deg/s) plantar flexion by maximal voluntary and submaximal electrical activation (MVA and SEA) was measured by real-time ultrasonography. Eccentric torque at 30 and 60 deg/s was significantly higher than isometric torque under SEA, but not under MVA. However, fascicle length did not significantly differ between isometric and eccentric trials under either condition. Therefore, the difference in developed torque by MVA and SEA cannot be explained by fascicle behavior. Under both MVA and SEA conditions, eccentric torque at 30 and 60 deg/s was equivalent. Similarly, fascicle lengthening velocities at 30 and 60deg/s did not show any significant difference. Such fascicle behavior can be attributed to the influence of tendinous tissue and pennation angle, and lead to a lack of increase in eccentric torque with increasing angular velocity.
KW - Force-velocity relationship
KW - Forcelength relationship
KW - Gastrocnemius and soleus muscles
KW - Tendinous tissues
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U2 - 10.1123/jab.25.2.111
DO - 10.1123/jab.25.2.111
M3 - Article
C2 - 19483255
AN - SCOPUS:66249102633
VL - 25
SP - 111
EP - 118
JO - Journal of Applied Biomechanics
JF - Journal of Applied Biomechanics
SN - 1065-8483
IS - 2
ER -